The present invention relates to a manufacturing method for a semiconductor memory device, and more particularly, to a method for forming a fine pattern in a semiconductor device.
According to a general method for forming a fine pattern of a semiconductor device, an underlying layer is formed over a semiconductor substrate. The underlying layer may be an insulating layer, a polysilicon layer, or a metal layer. A photoresist film is coated over the underlying layer. The photoresist film is exposed and developed with an exposure mask to form a photoresist film pattern. The photoresist film pattern is formed with a minimum pitch and a minimum line-width which can be formed by a current lithography process. In line/space patterns, the minimum pitch includes the pattern and the space with the equal width (1F). The underlying layer is etched using the photoresist film pattern as an etching mask to form an underlying layer pattern. The photoresist film pattern is removed to form a fine underlying layer pattern.
However, it is difficult to obtain high integration in semiconductor devices due to resolution limits in the current lithography process. As a result, there is a need to development equipment which can overcome resolution limits without much cost.